1. Field of the Invention
The present invention relates to an information processing method and apparatus therefor, for processing information of key input and of display and particularly adapted for use for example in a copier.
2. Description of the Prior Art
Microcomputers are employed in copiers and various electronic appliances for achieving complicated control in response to various input information. Usually input data are entered through input keys and the processed data are indicated by display units composed for example of light-emitting diodes. Conventionally hardware elements connected to a master computer (CPU) have been employed for processing or controlling such key input and data display. However such hardware elements cannot be designed to incorporate many functions because of the cost and complexity required, and a computer of a large capacity will be required if a part of such functions has to be borne by the master computer.
Also a conventional key input identifying device, utilized for identifying the actuated one among plural keys and transmitting the corresponding key signal to the computer, performs said identification by scanning all the keys connected to said device. For example in a copier, such key input identifying device is usually connected to numeral keys, a copy start key, a stop key, a paper-feed selector key etc., and the master computer is always called in response to the actuation of any key. In a copier it is desirable to accept only the stop key signal during a copying operation, but in practice a demand for key identification is given to the master computer in response to any key actuation. For this reason the master computer has to execute a program for identifying whether the stop key has been actuated whenever a key is actuated. In addition to the necessity for such key input identifying program, the master computer wastes considerable time for such identification in case other keys are actuated many times, and such time loss is a serious problem in case the master computer has to perform high-speed data processing.
In order to alleviate the burden of the microcomputers, there have been developed and made commercially available so-called key-and-display elements or devices for simplifying the procedure of key inputs and displays. Such key-and-display element is used for transmitting the actuated key to the microcomputer, and converting the data for preset or completed copy number into display signals for providing corresponding display.
The key-and-display element is generally unable to function alone but is designed to be controlled by a microcomputer. Consequently data transmission is required between the master computer and the key-and-display element in order to identify the proper function of the key matrix or the display circuit. The program required in the master computer for this purpose requires additional labor for preparation and additional memory.